初植和补植阔叶树对红壤丘陵区湿地松养分获取和转运的影响  

Effect of Initial Planting and Replanting Broad-Leaved Trees on Nutrient Acquisition and Translocation of Slash Pine in Red Soil Hilly Region

作　　者：夏成康 林勇 兰勇 吴高洋 王晟楠 陈伏生[1,2] Xia Chengkang;Lin Yong;Lan Yong;Wu Gaoyang;Wang Shengnan;Chen Fusheng(Jiangxi Provincial Key Laboratory of Silviculture College of Forestry,Jiangxi Agricultural University,Nanchang 330045;Key Laboratory of National Forestry and Grassland Administration on Forest Ecosystem Protection and Restoration of Poyang Lake Watershed,Jiangxi Agricultural University,Nanchang 330045;Jiangxi Guanshan National Nature Reserve Administration,Yifeng 336300;Jiangxi Forestry Resources Monitoring Center,Nanchang 330045)

机构地区：[1]江西农业大学林学院江西省森林培育重点实验室,南昌330045 [2]江西农业大学鄱阳湖流域森林生态系统保护与修复国家林业和草原局重点实验室,南昌330045 [3]江西官山国家级自然保护区管理局,宜丰336300 [4]江西省森林资源监测中心,南昌330045

出　　处：《林业科学》2024年第1期47-57,共11页Scientia Silvae Sinicae

基　　金：国家自然科学基金面上项目(31870427&32171759);江西省研究生创新专项资金(YC2022-s394)。

摘　　要：【目的】探究初植(同龄混植)和补植(异龄混植)阔叶树对湿地松养分获取和利用策略的影响,为湿地松林的科学管理提供参考。【方法】以种植于我国亚热带红壤丘陵区的湿地松林为对象,基于长期单种和混交试验平台,分别在林龄30年且立地条件相似的湿地松纯林、湿地松-木荷初植混交林、湿地松-木荷补植混交林(补植木荷14年)中构建5块20 m×20 m标准样地(共15块样地),采集湿地松标准木的根际土壤、细根、枝、新鲜叶和凋落叶样品,测定土壤和植物各器官的氮(N)、磷(P)含量,评估不同混交模式对根养分捕获能力、叶养分回收和树木养分转运的影响,揭示养分获取策略变化的驱动因素。【结果】混交阔叶树显著提高湿地松根际土壤的NH_4~+-N和矿质氮含量(P<0.05),但根际土壤养分含量在初植和补植混交林之间无显著差异(P>0.05);整体看,混交阔叶树提高湿地松各器官的N、P含量,其中初植混交效应比补植好。与纯林相比,初植混交林中湿地松根氮和磷捕获能力分别显著提高14.04%和46.16%,叶氮回收效率显著降低6.07%,磷回收效率显著提高15.49%。尽管补植阔叶树降低根养分捕获成本,但阔叶树根系抑制湿地松根系的养分捕获能力,导致补植混交林中湿地松根养分捕获能力和叶养分回收效率均无显著变化。此外,与纯林相比,初植混交林中湿地松运输根向枝、叶的N转运分别提高36.05%和15.61%,P转运分别降低35.13%和36.52%;补植混交林中N转运无显著变化,但运输根向枝、叶的P转运比在纯林分别降低53.21%和40.17%。【结论】混交阔叶树提高红壤丘陵区湿地松根际土壤和植株各器官的养分含量,改变湿地松养分获取策略,其中初植比补植更能促进湿地松的养分获取和利用。此外,养分在植物体内的转运过程可被检测,且反映根捕获和叶回收的权衡关系。【Objective】This study is intended to explore whether and how slash pine(Pinus elliottii)nutrient acquisition and utilization strategies are effected by the initial planting(even-aged mixed)and replanting(uneven-aged mixed)of broad-leaved trees,in order to provide a scientific basis for management of the slash pine forests.【Method】Our study was focused on slash pine,which are widely planted in the subtropical red soil hilly region of China.We conducted a long-term single-species and mixed experiment including three treatments(a 20 m×20 m plot per treatment)that pure slash pine plantation,mixed plantation of slash pine and Schima superba,mixed plantation of slash pine and S.superba(replanting S.superba for 14 years).At the age of 30 years and with similar site conditions,five 20 m×20 m plots in each treatment were established.The rhizosphere soil,fine roots,twigs,fresh and senesced needles of slash pine standard trees were collected.The nitrogen(N)and phosphorus(P)in soil and plant organs were determined to evaluate the effects of different mixed methods on root nutrient capture,needles nutrient resorption and nutrient translocation,and to reveal the driving factors of nutrient acquisition strategies.【Result】Initial and replanting broad-leaved trees increased the rhizosphere soil NH4+-N and mineral N(MN)in slash pine(P<0.05).But there was no significant difference in nutrient contents between the initial planting and the replanting.Mixed broad-leaved trees increased the N and P concentrations of each organ in slash pine,and the mixed effect of the initial planting was better than that of the replanting.Slash pine had 14.04%and 46.16%higher root capture ability of N and P in the initial mixed plantation than the pure plantation,respectively.The needles N resorption efficiency in the initial mixed plantation significantly decreased by 6.07%compared with slash pine pure plantation,and the needles P resorption efficiency in the initial mixed plantation significantly increased by 15.49%.The lack of signifi

关 键 词：针阔混交林 根捕获 叶养分回收 养分获取策略 木荷 

分 类 号：S725.2[农业科学—林木遗传育种]